Interactions within the turbulent boundary layer at high Reynolds number

摘要: Simultaneous streamwise velocity measurements across the vertical direction obtained in atmospheric surface layer (Re_τ ≃ 5 × 10^5) under near thermally neutral conditions are used to outline and quantify interactions between scales of turbulence, from very-large-scale motions dissipative scales. Results conditioned spectra, joint probability density functions conditional averages show that signature oscillations can be found whole wall region these interact with near-wall turbulence energy-containing eddies scales, most strongly a close wall, z^+ ≲ 10^3. The scale separation achievable appears key difference low-Reynolds-number picture, which structures attached known extend through full wall-normal extent boundary layer. A phenomenological picture coexisting interacting hairpin paradigm is provided here for high-Reynolds-number case. In particular, it inferred hairpin-packet conceptual model may not exhaustively representative region, but only = O(10^3), where mostly confined.